1. Field of the Invention
This invention relates to personal computers, and more particularly personal computers having a network of microcontrollers, each tied to one or more peripheral devices, such as a keyboard, which communicate with the system control processor (also known as a keyboard controller in an IBM or IBM compatible machine) to improve the overall system performance by eliminating the relatively slow peripheral communication with the system control processor and freeing up the system control processor for other tasks.
2. Description of the Prior Art
IBM type PC/AT compatible personal computers utilize a separate microprocessor as a system control processor (SCP). The SCP provides an interface between the host processor or CPU and peripherals, such as a keyboard. More specifically, the SCP handles the communication between the CPU and the keyboard. The IBM defined communication protocol between the keyboard and the SCP is relatively slow. Consequently, when the SCP is preoccupied with keyboard communication, it must finish that task before it can go on to other tasks. Accordingly, this keyboard interfacing task limits the overall system performance because the CPU must wait for the SCP to become free again.
Many known PC/AT type personal computers utilize an Intel type 8042 microprocessor as an SCP. The original PC type AT personal computers were introduced in 1983 with an Intel 80286 microprocessor. The 80286 microprocessors operated originally at 6 megahertz. In that environment, the use of an Intel type 8042 as a system control processor is adequate. However, personal computers today are much faster than the original IBM PC/AT computer. For example, some personal computers utilize an Intel 80386 as a CPU, which has an operating speed up to 33 megahertz. In such machines, the existing architecture, as shown in FIG. 1, can intensify the problems mentioned above and consequently severely limit the system performance. In addition to the problems mentioned above, newer machines, particularly the portable laptop type computers place additional burdens on the SCP. For example, in such computers, the SCP's tasks include battery power management, external bus expansion control and video functions such as backlighting control and LCD/CRT device selection. These additional tasks further degrade system performance.